1. Field of Invention
This invention pertains to an optical system for generating at least two light beams from a single light source. One light beam may be collimated for spot illumination, or both beams may be collimated. The system is particularly useful in flashlights because its low space requirements.
2. Description of the Prior Art
It is often advantageous to generate two or more light beams from a single light source along several axes. The beams may be used to illuminate different objects simultaneously. Alternatively one beam may be used to provide general or flood-type illumination while a second beam may be needed for concentrated or spot-type illumination. Several optical systems have been proposed in the past which can produce light beams from a single source however all them have various disadvantages as discussed more fully below.
In U.S. Pat. No. 2,408,643 a flashlight is disclosed with a head for projecting two light beams in opposite directions. The head includes two separate light bulbs with individual reflectors.
In U.S. Pat. Nos. 4,174,533 and 4,564,892 devices are disclosed which generate two beams which are directed toward the same area such as the mouth of a patient. The devices make use of paraboloidal reflectors to generate identical divergent beams directed towards a common area. These devices are used in the field of dentistry. In U.S. Pat. No. 1,147,344 a vehicle lamp is used with a reflector which is paraboloidal but generates only a single light beam.